The invention generally relates to medical products and, more particularly, the invention relates to devices for reducing backflow through a medical valve.
Medical valving devices commonly are utilized to valve fluids injected into and withdrawn from a patient. One exemplary type of medical valving device, known in the art as a xe2x80x9ccatheter introducer,xe2x80x9d maintains a sealed port for accessing the patient""s vasculature. Use of such a valve enables vascular access without requiring the patient""s skin to be repeatedly pierced by a needle. Moreover, catheter introducers are constructed to withstand a range of back-pressures produced by a patient""s blood pressure, thus minimizing blood loss resulting from fluid injections or withdrawals.
Fluid commonly is transferred to/from a patient by inserting a syringe into a medical valve, thus communicating with the patient""s vasculature. Problems arise, however, when the syringe is withdrawn from the valve. More particularly, a back pressure produced by withdrawing the syringe undesirably can cause blood to leak proximally into various parts of the valve. In addition to coagulating and impeding the mechanical operation of the valve, blood in the valve also compromises the sterility of the valve.
In accordance with one aspect of the invention, a medical valve has a translating member that enlarges the volume of the interior of the valve when the valve is in an open mode (permitting fluid flow), and decreases the volume of the interior when the valve is in a closed mode (preventing fluid flow). This varying volume should substantially eliminate drawback into the valve. To that end, the valve includes a housing having an inlet and an outlet, and a fluid channel extending between the inlet and the outlet. The fluid channel includes a variable volume region. The valve further includes the above noted translating member, which is secured to the housing and at least partly bounds the variable volume region. The translating member has at least a portion that moves distally when the valve transitions from the closed mode to the open mode. The distal movement of the translating member enlarges the volume on the variable volume region.
In some embodiments, the translating member is substantially coaxial with the majority of the fluid channel. The translating member may include a securing portion that normally maintains the noted portion of the translating member in a position that minimizes the volume of the variable volume region. In such case, the securing portion may stretch when the valve transitions from the closed mode to the open mode, and retract when the valve transitions from the open mode to the closed mode.
The valve also may include a guide member extending into the translating member. The guide member may include at least a portion of the fluid channel. The fluid channel may include a translating fluid channel extending through the translating member. The translating fluid channel illustratively has substantially the same shape in both the open and closed modes.
In some embodiments, the translating member comprises a bellows. In other embodiments, the translating member may include a compressible portion that compresses when the valve transitions from the closed mode to the open mode. Among other things, the valve may include a swabbable seal, and/or may be a luer activated valve.
In a manner similar to the above noted aspect of the invention, other aspects of the invention include a medical valve (having an open mode that permits fluid flow and a closed mode that prevents fluid flow) that also has a translating member. The valve is capable of transitioning between the open mode and the closed mode, and includes a housing having an interior with a primary fluid channel with a variable volume region. The noted translating member bounds the variable volume region and is secured to the interior of the housing. The translating member has a translating member fluid channel that permits fluid flow through the translating member. The primary fluid channel thus includes the translating member fluid channel. At least a portion of the translating member longitudinally moves when the valve transitions from the closed mode to the open mode. Such longitudinal movement enlarges the volume of the variable volume region.